The threat of terrorism is increasing all over the world. As for chemical terrorism using a chemical warfare agent (hereinafter referred to as “chemical agent”), in particular, the production of such a chemical agent is easier when compared with production of nuclear weapons and, once really committed, it caused a serious damage, so that every country is taking strict precautions against it. In Japan, too, a chemical agent was misused in the Matsumoto and Subway sarin gas incidents, among others, and it is urgent that measures be taken against chemical agents. Further, it has become evident that chemical weapons estimably produced by the old Japanese army during the wartime are buried in China and in Japan; reportedly, if chemical agents are allowed to leak out into the environment during construction work, for instance, it caused health damages in some instances. It is required that abandoned chemical weapons and chemical agents retained therein be dug up, recovered and rendered harmless safely and promptly.
In case of actual use or leakage of a chemical agent, it is necessary to immediately know the chemical agent species and the concentration thereof in the atmosphere and utilize the information obtained in inhabitant evacuation, treatment and decontamination. Therefore, a chemical agent detector utilizing the technology of mass spectrometric analysis, which is known as a method excellent in speed, sensitivity and selectivity among various analytical methods, has been proposed (JP 2004-158296 A and JP 2004-286648 A). Referring to FIG. 11, the prior art chemical agent detector utilizing the technique of atmospheric pressure chemical ionization mass spectrometry is described. The chemical agent detector is constituted of a sample introduction section 1, an ionization section 2, a mass spectrometry section 3, a control section 4, a suction pump 5, a computer 6 for measurement and processing and a vacuum pump 7. A sample 16 introduced into the sample introduction section 1 is heated and vaporized. The sample, now gaseous, is led to the ionization section 2 by means of the suction pump 5. The sample introduced into the ionization section 2 is sent to and ionized in a corona discharge region. The ions formed are led to the mass spectrometry section 3 for mass spectrometric analysis. The results of the mass analysis are processed by the measurement/processing computer 6 for displaying. When the results obtained show the characteristic features of the results of measurement of a chemical agent, the chemical agent is regarded as having been detected.
As a gas monitoring apparatus which utilizes atmospheric pressure chemical ionization mass spectrometry, an exhaust gas monitoring apparatus is disclosed in JP 2000-162189 A. In this apparatus, an exhaust gas is taken into an atmospheric pressure chemical ionization mass spectrometer and the concentration of dioxin and related compounds contained in the exhaust gas is displayed. JP 2005-274566 A describes that lewisite, diphenylcyanoarsine and/or diphenylchloroarsine is subjected to derivatization treatment and then analyzed by a gas analyzer.